Wellmar



0v 5; WELLMAR 2,518,104

I APPARATUS FOR DRYING MATERIAL IN THE FORM OF WEBS' Filed Sept. 27, 1946 3 Sheets-Sheet 1 Fig.1 H

INVENTOR Sven Wei/mar flttorney Aug. 8, 1950 s. WELLMAR 2,518,104

APPARATUS FOR DRYING MATERIAL IN THE FORM OF WEBS Filed Sept. 27, 1946 3 Sheets-Sheet 2 I Fig.5 //2 4 4 J [/vvE/v-roR SVE/V WELL/4AA! a MM Attbrney Aug. 8, 1950 s. WELLMAR 2,518,104

APPARATUS FOR DRYING MATERIAL IN THE FORM OF WEBS Filed Sept. 27, 1946 s Sheets-Sheet 5 INVENTOR Sven Wei/mar By MM Aitor'ney Patented Aug. 8,- 19 50 APPARATUS FOR DRYING MATERIAL IN THE FORM OF WEBS Sven Wellmar, Abrahamsber'g, Sweden, assignor to A. B. Svenska Fliiktiabriken, Stockholm,

Sweden Application September 21, 1946, Serial No. 699,821 In Sweden June 15, 1945 9 Claims. (Cl. 34-159) In the process of drying material in the form of webs, for instance, pulp, paper and the like. it is known to employ apparatus which, by a number of interposed floors or heat radiators, are divided into channels for said web. These drying apparatus are provided with fans circulating dry air within the apparatus, and the fans are usually arranged on those sides of the apparatus which are parallel with the path of movement of the web. In the embodiments known per se, the blow in and exhaust openings for the air cir-. culating fans are arranged in the two longitudinal walls of the apparatus, opposite one another for the same channel. Placing the openings in this manner causes, however, certain drawbacks specially in connection with the air conducting and air flow resistance. The path of the circulating air shows a plurality of transverse turns and further whirling motions arise providing a relatively great air flow resistance.

The above construction is, however, not economical because it requires that half the fans and Ian-boxes are of right-hand construction and half of left-hand construction, thus increasing manufacturing costs.

The present invention has for its object to provide an improved air introducing drying apparatus of the kind referred to providing a reduced resistance for the circulating air in the apparatus. The invention is substantially characterized in that the blow in and exhaust openings for the air circulating fans, to and from the channels in the drying apparatus, are provided in sidewalls of the apparatus, opposite one another and alon the path of movement of the web, in the manner that air, blown into a channel from one side of the apparatus, will be exhausted at the other side of the apparatus from a channel positioned immediately above or below the channel into which the air was introduced. With the blow in and exhaust openings placed in this manner there is obtained not only a reduced resistance for the circulating air but the cross over means comprising the air circulating fans and fan-boxes may all be made identically.

The invention is illustrated by way of examples in the accompanying drawings.

In the drawings Figure 1 shows diagrammatically a horizontal section through a drying apparatus arranged according to the invention;

Figure 2 is a vertical section on the line II-II oi Figure 1;

Figure 3 is a vertical section, taken similar to Figure 2, of a modification of the invention;

Figure 4 is a horizontal section through a modiiled embodiment of the apparatus according to Figure l;

Figure 5 is a vertical section on the line V-V of Figure 4;

Figure 6 is a vertical section on the line VI-VI of Figure 1;

Figure '7 is a vertical section on the line VII-VII of Figure l; and

Figure 8 is a fragmentary view similar to Figure 7 of a modification.

In the figures, I designates a drying casin intended for drying material in form of webs. Between the longitudinal sidewalls 2 and 3 of the drying casing interposed plates or heat radiators t are arranged dividing said casing i from its top to its bottom into a number of horizontal chan nels A, B, C, D, etc., for the web which is designated 5. Said interposed plates 4 may, as illustrated in Fig. l of the drawing, terminate a short distance from the end walls 23 of said drying casing i, but preferably every second plate 4 may extend against one of the end walls 23, as shown in Figure 8, to provide a channel for the web running zigzag through the casing. Fan-boxes 6 and 1 are provided on each side of said drying casing i. The fan-boxes 6 and I are divided by interposed vertical partitions 8 and 9- into a suction chamber and a pressure chamber, and screw fans illa and llib are placed in openings-in said interposed partitions 8 and 9. Said suction chambers as well as pressure chambers are connected with said drying channels by openings. For example, the blow in openings 2 (Fig. 6) in the side wall 2 are connected to channels A, C, etc., and the exhaust openings I22 are connected to channels B, D, etc. Corresponding numerals for the blow in and exhaust openings in sidewall 3 are 3 and I23 respectively. The curved walls a and lib serve as guiding bafiies to direct the drying medium enterin a channel from the opposite sides of the casing, into opposite directions.

In the modification shown in Figure 3, heat radiators it together with bailie or guide-plates ii and i8 constitute here the channels in the drier. A conveyor ii for the web is arranged in the channels. The conveyor flights I'I aresupported by iron supports l8 and IS. The inlet and exhaust openings H2, I22 and H3, I23 in the side walls extend practically the full height and are divided by the battles i5 and It. In order to reduce drop of pressure, caused by passing or air through the openings in the longitudinal sidewalls of the drier, the guide plates is and it are bent round the iron supports l8, l9 providing a rounded front edge. Since every second pair 0i ment of the air.

follows.

The position of the openings in the ,longitudinal'sidewalls of the drier will be clear from Figures 6 and 7. Figure 6 shows their positions in the wall 2 (Figs. 1 and 3) and Figure 7 their po-' sitions in the wall 3 (Fig.

When the apparatus is in operation the inlet opening H2 to a channel is in communication with the outlet opening I23 of an immediately below positioned channel and the inlet opening 3 with the outlet opening .122 for the same channels.

Arrows in Figure 1 illustrate the path of move- The apparatus functions as Air is supplied to the casing through inlet 2'5 and is discharged therefrom through the discharge opening 26. The air is sucked by the fan Illa from the suction-chamber in the crossover fan-box B and is driven over the pressure chamber through the openings H2 into one of the channels, for example, channel C in the drier. The air here runs horizontally along the interposed plate 4 towards one of the endwalls of the drier at the right where it turns downward around the edge of the interposed plate and enters the underlying suction channel D from which it escapes through the opening I23 into the suction-chamber in the fan-box 1. The air then is forced by the fan lllb through the opening I I3 into the overlying channel C in which it runs towards the other endwall of the drier at the left, where the air turns down into the underlying channel D from which it departs through the opening I22 into the suction-chamber in the fanbox 6. In this manner a closed circulating system for the air is obtained.

A modified embodiment of a drier according to the present invention is illustrated in Figures 4 and 5. The air-circulating fans are in this case centrifugal fans or air-turbines 30 sucking air from special suction-chambers 3| arranged between the exhaust openings for the channels and the wheels of the fans. Otherwise, the circulation of the air occurs in the same manner as previously described.

In Figure 7 arrows indicate inlet and outlet pipes to the casing I for ventilating air.

What I claim as new and desire to secure by Letters Patent is:

1. An apparatus for drying web material comprising a casing having an inlet and an outlet opening for the web, plates in said casing dividing it into an even number of longitudinal substantially horizontal channels arranged one above the other and communicating inpairs in such manner that the upper channel of each pair at its both ends is in communication with the channel positioned immediately below so as to form a zigzag-way in said casing for said web, an inlet and an outlet pipe in said casing for entrance and escape respectively of drying medium, a vertical box at the middle of each longitudinal side-wall of said casing extending substantially the depth thereof, a partition in said box dividing it into two vertical chambers, said partition having openings and a fan in each opening, said fans being arranged to operate in the manner that one of said vertical chambers acts as a pressure chamber and the other as a suction chamber for the drying medium of the apparatus, said pressure chamber having a vertical rowot outhaving a vertical row of inlet openings for said drying medium communicating the remaining channels in said casing with said suction chamber, said alternate channels which are in communication with the outlet openings from the pressure chamber of the box at one side of the casing being also in communication with the outlet openings from the pressure chamber of the box at the other side thereof, and said alternate channels which are in communication-with the inlet openings to the suction chamber of the box at one side of the casing being also in communication with the inlet openings to the suction chamber of the box at the other side thereof, said vertical row of outlet openings from the pressure chamber in the box on one side of said casing being arranged on one side of a vertical transverse plane through said casing, and said vertical row of outlet openings from the pressure chamber in the box on the other side thereof being arranged on the other side of said vertical transverse plane so that the streams of drying medium entering the channels through said outlet openings from said pressure chambers do not meet and interfere with each other in the channel's,

2. An apparatus as specified in claim 1 wherein said plates dividing said casing into channels comprise heat-radiators.

. one of said boxes and said vertical row of outlet openings pertaining to the other of said boxes are arranged at the same side of a central vertical plane crossing said casing and the remaining rows of inlet and outlet openings are positioned at the other side of said central vertical plane in said boxes.

4. An apparatus as specified in claim 1 wherein said boxes are identical.

5. An apparatus as specified in claim 1 wherein the walls of said boxes are formed as guiding means for directing such two streams of drying medium which are entering one of said channels from opposite sides of said casing, into opposite directions towards the ends of said channel without letting said streams of drying medium cross one another.

6. An apparatus for drying web material comprising: a casing having opposed side and other walls and an inlet and outlet for the drying gas;

nels which extend horizontally, communicate at opposite ends with each other, provide a zigzag path for the web, a right path for the flow-of gas from the right side of a centrally disposed vertical plane, passing transversely through the partition, outwardly through the pressure chan- 'nel and thence inwardly through the suction channel to the right side of said plane and a corresponding left path on the left side of said plane passing outwardly through the pressure channel and inwardly through the suction channel; means on the right side of said plane providing, for the right gas path, a gas inlet opening through one side wall into the pressure channel and a gas outlet opening on the opposite side wall for the suction channel; means on the left side oi said plane providing, for the leit gas path, a gas inlet opening on said opposite side wall for the pressure channel and a gas outlet opening on said one sidewall for the suction channel; and corresponding cross-over means on each side wall providing a suction chamber for the gas outlet, a pressure chamber for the gas inlet and gas blowing means having a suction inlet and pressure outlet respectively connected to the suction and pressure chambers.

7. The apparatus of claim 6 wherein: the crossover means on opposite side walls are interchangeably constructed.

8. The apparatus oi claim 6 wherein: additional partitions are provided correspondingly dividing said casing into one or more pairs of additional superposed pressure and suction channels, the channels 01' each additional pair extending horizontally, communicating at opposite ends with each other, providing a zigzag path for the web and corresponding right and left paths for the flow of gas; means on the right side 01' said plane providing, for each additional right gas path, correspondingly positioned gasinlet and outlet openings; means on the left side of said plane providing for each additional left gas path, correspondingly positioned gas inlet and outlet openings; each cross-over means has its suction chamber connected to the additional correspondingly positioned gas outlets, and its pressure chamber connected to the additional correspond-- ing positioned gas inlets.

9. The apparatus of claim 8 wherein: the crossover means on opposite side walls are interchangeably constructed.

t SVEN WELLMAR.

REFERENCES CITED YThe following references are of record in the file 01' this patent:

UNITED STATES PATENTS 

